The device of the invention is used when a vehicle wheel has to be removed from the shaft for repair or maintenance, for instance, or when the wheel has to be removed from the shaft to replace a worn tire with a new one, or when a spare wheel has to be installed on the road due to a tire failure.
The weight of the vehicle wheel itself is relatively high so that it may be dangerous to handle it merely by human power. Therefore auxiliary means are required for changing the wheel. Labor legislation requires that specified lifting weights should not be exceeded. In addition, the handling of the vehicle wheel requires accuracy, as the disc wheel is installed tightly on the shaft of the vehicle, and it is important that the vehicle wheel can be handled easily so that the placement of the wheel on the vehicle shaft can be shifted, that is, in practice, rotated accurately. The change of the vehicle wheel is especially difficult when the spare tire has to be installed in the vehicle in field conditions, because the driver nowadays has to face the problem alone and the conditions are difficult.
It is previously known to carry out the change of a worn or e.g. damaged wheel of a vehicle, such as a lorry for heavy equipment, by using auxiliary means. Solutions known from the prior art comprise long rolls to be positioned under or on both sides of the tire, and the vehicle wheel is then lifted by moving the rolls. Such a structure is disclosed e.g. in the publications DE - 3 047 844; U.S. Pat. No. 4,690,605; and EP - 0 125 551. EP - 0 114 147 discloses a structure comprising a means by which the wheel can be locked in position by pressing said means against the disc wheel.
The prior art has many disadvantages. When the tire of the vehicle wheel is damaged, e.g. blown out, the handling of the vehicle wheel is very difficult by means of the existing devices. A damaged vehicle tire, e.g. a tire broken completely apart, in which most of the tire portion of rubber has disappeared, cannot be gripped appropriately by the prior devices.
A further disadvantage of certain other known solutions is that the device is such in structure that it comprises various means positioned close to the end of the shaft positioned in the middle of the disc wheel, and so the inner wheel of twin wheels cannot, for instance, be removed by the prior art devices, because the parts of the device come into contact with the shaft end when one attempts to push the device towards the inner wheel of the twin wheels.
U.S. Pat. No. 4,022,341 discloses a device for lifting a vehicle wheel from a shaft. The wheel is handled with this device by the disc wheel groove, but the support means to be fitted into the disc wheel groove is of such shape that the wheel can only be lifted by means of it, as the support means comprises two adjacent narrow plate portions on which the wheel cannot be rotated. In addition, lifting in this device is carried out from the upper edge of the device by means of a lifting hook and a wire rope.